1. Field of the Invention
The present invention relates to a method and apparatus for recording data, a method and apparatus for reproducing data, and a recording medium. More particularly, the invention relates to a method and apparatus for recording data, a method and apparatus for reproducing data, and a recording medium, which allow data to be recorded in a parallel fashion in a short time.
2. Description of the Related Art
The present applicant has proposed, for example in Japanese Unexamined Patent Publication No. 6-131371 (corresponding to U.S. Pat. No. 5,619,570), Japanese Unexamined Patent Publication No. 6-215010, and Japanese Unexamined Patent Publication No. 6-301601 (corresponding to U.S. Pat. No. 5,717,953), a system in which data such as video data, audio data, a character, and/or a computer program (in particular, data in digital form) is supplied from an information supplying apparatus to a portable type user terminal including a recording medium such as a semiconductor memory thereby providing various services.
In this system, a user may carry a user terminal with him/her to a location where an information supplying apparatus is installed to receive data such as audio data. The user may enjoy listening to, for example, music by reproducing the received data on his/her user terminal. In this system, the user can obtain music data without having to buy a CD (Compact Disc) or a magnetic tape on which audio data is recorded. When the user has become tired of that music, he/she may obtain another audio data via the information supplying apparatus and enjoy listening to new music.
The user terminal used in such a system needs high portability. To meet this requirement, it is desirable that the recording medium used in the user terminal be formed of a nonvolatile memory such as a flash memory capable of holding data without needing backup with a battery or the like.
However, the flash memory needs a rather long programming time in the process of actually writing (recording) input data into a data flash memory cell compared with the data inputting time required to input data to be written (recorded). When a greater amount of data is written than can be input at a time to the flash memory, it is required to wait for a period of time equal to or longer than the programming time after inputting data before inputting next data. Because of such a waiting time, it takes a long time to supply data to one user. This causes another user to wait before he/she receives data because the information supplying apparatus is used by a great number of users. Thus, the information supplying apparatus cannot supply data to a large number of users.
To solve the above problem, the present applicant has proposed a technique of reducing the data writing time by writing data in a parallel fashion into a flash memory formed of a plurality of chips (hereinafter, such a technique will be referred to as a parallel recording method).
In the parallel recording method, data is input to one chip of the plurality of flash memory chips, and next data is input to another chip after completion of inputting the previous data. Similarly, following data is input to the memory chip by chip after completion of inputting previous data. This technique allows data to be input to a chip when previous data is being written into another chip. This makes it unnecessary to wait until a programming time associated with one chip has elapsed before starting to input next data to another chip, and thus it becomes possible to reduce the period of time required to write data.
When data is written into, for example, two chips of the plurality of flash memory chips according to the parallel recording method, a piece of data with a predetermined size is first input to one chip (first chip) and another piece of data with the predetermined size is input to the other chip (second chip) after completion of inputting the previous piece of data to the first chip. When inputting of data to the second chip is completed, still another piece of data with the predetermined size is input to the first chip. However, there is a possibility that writing of the previous piece of data with the predetermined size to the fist chip is not completed when another piece of data is tried to be input to the first chip. In this case, data to be input at this time has to wait until the writing of the previous data is completed. This makes it impossible to achieve an effective increase in the writing speed according to the parallel recording method.
In a specific case where the programming time per flash memory chip is nearly equal to but slightly smaller than 3 times the data inputting time, if data is written into four or more flash memory chips according to the parallel recording method, then it is possible to eliminate the waiting time which would other wise arise from the programming time.
Thus, if a user has a flash memory consisting of four or more chips, it is possible to write data without creating a waiting time by writing data into four more chips according to the parallel recording method.
However, in the case where the writing of data according to the parallel recording method is performed for four or more particular chips arbitrarily selected by a user, there is a possibility that a large amount of data is recorded preferentially in particular one or more chips and, as a result of such preferential writing, the number of flash memory chips available for recording data can drop to three or less. In this case, it is no longer able to write data into four or more flash memory chips according to the parallel recording method, and thus a waiting time associated with the programming time is required. As a result, an effective increase in the writing speed according to the parallel recording method cannot be achieved.
In view of the above, it is an object of the present invention to provide a technique of achieving a maximum increase in the writing speed according to the parallel recording method.
According to an aspect of the invention, there is provided a recording apparatus for recording data in a parallel fashion in a recording area of a recording medium, the recording area being managed in units of predetermined blocks, the recording apparatus comprising: construction means for constructing one or more parallel block sets each consisting of one or more blocks the number of which is determined in accordance with a minimum number of blocks which allows a waiting time to become minimum in the process of recording the data in the parallel fashion into one or more blocks of the recording medium; and recording means for recording the data into the one or more blocks of the one or more parallel block sets.
According to another aspect of the invention, there is provided a recording method for recording data in a parallel fashion in a recording area of a recording medium, the recording area being managed in units of predetermined blocks, the method comprising the steps of: constructing one or more parallel block sets each consisting of one or more blocks the number of which is determined in accordance with a minimum number of blocks which allows a waiting time to become minimum in the process of recording the data in the parallel fashion into one or more blocks of the recording medium; and recording the data into the one or more blocks of the one or more parallel block sets.
According to another aspect of the invention, there is provided a recording medium for recording data in a parallel fashion in a recording area which is managed in units of predetermined blocks, wherein one or more parallel block sets are constructed which consist of one or more blocks the number of which is determined in accordance with a minimum number of blocks which allows a waiting time to become minimum in the process of recording data in the parallel fashion into the one or more blocks of the recording medium, and the data is recorded in the parallel fashion in the one or more blocks of the one or more parallel block sets.
According to still another aspect of the invention, there is provided a recording medium for recording data in a parallel fashion in a recording area which is managed in units of predetermined blocks, wherein the minimum number of blocks which allows a waiting time to become minimum in the process of recording the data in the parallel fashion into one or more blocks or information required to determine the minimum number of blocks is recorded on the recording medium.
According to still another aspect of the invention, there is provided a reproducing apparatus for reproducing data from a recording medium, the data being recorded in a parallel fashion in a recording area of the recording medium, the recording area being managed in units of predetermined blocks, the reproducing apparatus comprising reading means for reading the data from the recording medium wherein the data is recorded in such a manner that one or more parallel block sets are constructed which consist of one or more blocks the number of which is determined in accordance with a minimum number of blocks which allows a waiting time to become minimum in the process of recording the data in the parallel fashion into said one or more blocks of the recording medium, and the data is recorded in the parallel fashion in the one or more blocks of the one or more parallel block sets.
According to still another aspect of the invention, there is provided a reproducing method for reproducing data from a recording medium, the data being recorded in a parallel fashion in a recording area of the recording medium, the recording area being managed in units of predetermined blocks, the method comprising the step of reading the data from the recording medium wherein the data is recorded on the recording medium in such a manner that one or more parallel block sets are constructed which consist of one or more blocks the number of which is determined in accordance with a minimum number of blocks which allows a waiting time to become minimum in the process of recording the data in the parallel fashion into the one or more blocks of the recording medium, and the data is recorded in the parallel fashion in the one or more blocks of the one or more parallel block sets.
According to still another aspect of the invention, there is provided a recording apparatus for recording data in a parallel fashion in a plurality of recording areas of a recording medium, the plurality of recording areas being managed in units of predetermined blocks, the recording apparatus comprising: construction means for constructing one or more parallel block sets each consisting of one or more blocks used to record the data, in such a manner as not to create a significant difference in the size of a writable area available for recording data among the plurality of recording areas; and recording means for recording the data into the one or more blocks of the one or more parallel block sets.
According to still another aspect of the invention, there is provided a recording method for recording data in a parallel fashion in a plurality of recording areas of a recording medium, the plurality of recording areas being managed in units of predetermined blocks, the method comprising the steps of: constructing one or more parallel block sets each consisting of one or more blocks used to record the data, in such a manner as not to create a significant difference in the size of a writable area available for recording data among the plurality of recording areas; and recording the data into the one or more blocks of the one or more parallel block sets.
According to still another aspect of the invention, there is provided a recording medium for recording data in a parallel fashion in a plurality of recording areas which are managed in units of predetermined blocks, wherein the data is recorded in such a manner that one or more parallel block sets each consisting of one or more blocks used to record the data are constructed in such a manner as not to create a significant difference in the size of a writable area available for recording data among the plurality of recording areas, and the data is recorded in the parallel fashion in the one or more blocks of the one or more parallel block sets.
According to still another aspect of the invention, there is provided a reproducing apparatus for reproducing data from a recording medium, the data being recorded in a parallel fashion in a plurality of recording areas of the recording medium, the plurality of recording areas being managed in units of predetermined blocks, the reproducing apparatus comprising reading means for reading data from said recording medium on which said data is recorded in such a manner that one or more parallel block sets each consisting of one or more blocks used to record the data are constructed in such a manner as not to create a significant difference in the size of a writable area available for recording data among said plurality of recording areas, and said data is recorded in the parallel fashion in the one or more blocks of the one or more parallel block sets.
According to still another aspect of the invention, there is provided a reproducing method for reproducing data from a recording medium, the data being recorded in a parallel fashion in a plurality of recording areas of the recording medium, the plurality of recording areas being managed in units of predetermined blocks, the method comprising the step of reading data from said recording medium on which the data is recorded in such a manner that one or more parallel block sets each consisting of one or more blocks used to record the data are constructed in such a manner as not to create a significant difference in the size of a writable area available for recording data among the plurality of recording areas, and the data is recorded in the parallel fashion in the one or more blocks of the one or more parallel block sets.